Combustion apparatus



Jan. 9, 1940.- 5, gra 2,186,156

COMBUSTION APPARATUS.

Filed April 14, 1939 3 Sheets-Sheet l I N VE NTOR. 557V l ALJEAN @MZMZJMATTORNEY.

1940- B. VALJEAN COMBUSTIQN APPARATUS Filed April 14, 1939 :5Shets-Sheei', 2

-' INVENTOR.

557V V4LJF/4/V Fwd/41,4

ATTORNEY.

Jan. 9, 1940. B. VALJEAN I v 2,186,156

COMBUSTION APPARATUS Filed April 14, 1939 5 Sheets-Sheet I5 I r v V Q VI I 7 I H H I Q Q o o 4 %o o o- INVENTQR 55 N 144/. JEAN ATTORNEY.

Patented Jan. 9, 1940 PATENT OFFICE COMBUSTION APPARATUS Ben Valjean,Lansing, Mich, assignor to Motor Wheel Corporation, Lansing, Mich, acorporation of Michigan Application April 14, 1539, Serial No. 267,81115 Claims. (01. 158-91) This invention relates to vaporizing pot typeburners of the type illustrated in my prior Patent No. 2,073,270, andthe present invention is an improvement upon the invention disclosed inmy said prior patent.

The present application is a continuation in part of and substitute formy co-pending applications Serial No. 127,601 filed February 25, 1937for Combustion apparatus, and Serial No. 231,670

filed September 26, 1938 for Combustion apparatus.

structurally, the present improvement consists in providing an inclinedor biased baffle in place of the horizontal baflle disclosed in my prior1 Patent No. 2,073,270. The advantage obtained by the presentimprovement over the advantages of my prior patent is a clean and stablefire throughout both the low and intermediate operating stages ascompared with the clean fire obtained by my prior patented structureeither at the lowermost or at the intermediate operating stage, but notat both.

The present invention will best be understood in connection with areview of the entire develop- 35 ment of which it forms a part. Myoriginal invention resides in the discovery that one of the reasons whya clean fire could not be obtained in the lower operating stages of pottype burners was because the premixing action of the burner 30 at thosestages was adversely affected by eddy currents. This difliculty wasovercome without adversely affecting the operation of the burner by theuse of a baflie positioned as disclosed in my prior patent.

.85 However, it was found that a single horizontal baffle was notsufficient to obtain a clean fire at both the low and the intermediateoperating stages. Following that discovery, I proposed to use twobafiles instead of one, located in such a 40 position as to eliminateeddy currents at both the intermediate and the lower operating stages.This development is disclosed in my copending application Serial No.70,300. However, upon using two baflles I found that the capacity of the4!!- burner was somewhat reduced, which I believe was because the twobafiles interfered with the reflection of heat at the higher operatingstages to such an extent as to interfere with the vaporization of liquidfuel, and thereby reduce the 50 capacity of the burner. Thus, a cleanfire throughout both the lower and intermediate stages could not beobtained through the use of two horizontal bafiles without somesacrifice of the overall capacity of the burner. While this ob- 55jection is not so great as to completely destroy the benefit of the useof two bailles, the advantages of the two bailles are somewhat offset byreason of this fact.

The present invention is the result of my efforts to attain the benefitsof the use of two baflles, namely, a clean fire throughout both thelower and intermediate operating stages, without thedisadvantages of theuse of two baflles, namely, a reduction in the capacity of the burner.This is accomplished in accordance with the 10 present invention by theuse of an inclined or biased baflle having its lower edge in theposition which would be occupied by the lower of two baflles, and itsupper edge in the position which would be occupied by the upper 01' twobattles, in a burner utilizing two baflles. I have discovered that sucha biased baflie accomplishes almost as I advantageous results as the useof two horizontal baflles, while maintaining the samecapacity of theburner as is obtained when a single bailie is 0 used.

It is important, however, to avoid any direct impingement of air againstthe biased baflle, otherwise much of the advantages of the use of abaflie will be destroyed by the maintenance of combustion at the pointof such impingement, even at the high fire stage of operation. This islikely to cause smoke and the deposit of carbon in the region of theimpingement. V

In the drawings: 9

Figure 1 is a sectional view of a combustion device of the space heatingtype including a burner embodying the present invention;

Figure 2 is an enlarged sectional view of the burner shown in Figure 1;

Figure 3 is a top view of the burner, partly in section, taken on theline 33'of Figure 2;

Figure 4 is an elevational view of a blank forming one-half of theburner wall;

Figure 5 is an elevational view of a blank form ing the other half ofthe burner wall;

Figure 6 is an enlarged sectional view of substantially the same burneras shown in the preceding figures, equipped with a slightly modifiedform of baflle; and

Figure 7 is a top view of the burner shown in Figure 6, partly insection, taken on the line 1--'| of Figure 6.

The space heater illustrated in Figure 1 includes an outer casing l0,forming an upper combustion chamber II and a lower air chamber l2.

A burner 13 is located in the air chamber l2. The combustion chamber IIis provided with a door 14, a top l5, and a flue outlet It. The flueoutlet I6 is connected to a chimney II by a pipe l8. Pipe I8 is providedwith a conventional form of draft regulator shown at II.

The burner IS, the details of which will be described presently, ismounted in the casing ID by means of what may be termed a jack screw 20.Screw 20 is threadedly mounted in the intersecting portions of thedetachable legs 2|, of which there are preferably}. Legs 2| are securedto an intumed flange 22 at the bottom of the casing In by means of bolts23. The legs 2| do not close the bottom of air chamber l2 so that thischamber is open to the atmosphere. Casing I 0 and burner II are formedwith cooperating shoulders lfla and I 3a respectively. Burner shoulderl3a is held against the casing shoulder Illa by suitable adjustment ofthe screw 20. A seal, preferably asbestos, is positioned between theshoulders Illa and Na to prevent the passage of air between the burnerand the casing at this point.

Oil is supplied to burner I: from a source not shown through the 011line 24 with which is associated a manually operable regulating valve,i1- lustrated diagrammatically at 24a. Any conventional form ofautomatic valve may be substituted for the manually operated valve 24a.

Burner l3 includes a thin sheet metal side section 25, a heavier metalbottom wall 26 permanently secured to the lower edge of the sidesection, and a heavy metal top wall 21 removably secured within theupper edge of the side section. A sectional anti-explosion ring 22 isshown mounted upon top wall 21.

The anti-explosion ring 28 is so named because it prevents completeextinguishment of the fire in the combustion chamber II, and as a resultexplosions are prevented. The anti-explosion ring 28 is arranged withrespect to the openings 35 whereby at least some of the air enteringtherethrough impinges against the ring; and to efiectively preventcontact therewith of any great quantity of fuel vapors. Thus, there isalways maintained adjacent the inner periphery of the anti-explosionring a mixture of air and fuel vapors containing a sumcient quantity ofair to support combustion. So long as fire is maintained in theapparatus the possibility of an explosion because of the generation ofan excess of fuel vapors is effectively eliminated.

Top wall 21 and the anti-explosion ring 28 are preferably formed of castmetal. Top wall 21 is provided with a large central opening 21a. The

anti-explosion ring 28 is also formed with a central opening 28a,somewhat larger than opening 21a.

The sheet metal side section 25 is of generally cylindrical form, beinghere shown as of substantially uniformly increasing diameter from itslower edge to its upper edge. So far as the present invention isconcerned, the side section may be either tapered as shown, a truecylinder, or of oval cross section. Accordingly, the words generallycylindrical are here used in the broader sense as including all of thesevarying forms.

Adjacent the upper extremity the side section 25 is provided with aradially inwardly extending rib 29 and the outwardly extending rib orshoulder 130.. Top wall 21 is mounted upon the radially inwardlyextending rib 29. The sectional anti-explosion ring 28 is in turnmounted upon the top wall 21. The anti-explosion ring 28 includes thedepending legs or vanes 30 which space the anti-explosion ring fromthetop wall 21. At its upper edge the side section 25 is indentedradiallyinwardly, as indicated at II, to lock the anti-explosion ring inplace.

The bottom wall 25 is of pan-like formation, in cluding the cylindricalside portion 28a, which togetherwith side section 25 forms the side wallof the burner. 'The bottom is secured to the side section 25 bytelescoping the cylindrical side 25 within the upper edge of the bottomsection 26a. It is secured in this position by any suitable securingmethod, as by welding.

The bottom wall is provided with a fuel reservoir in the form of a sump32 adjacent one side thereof. This sump is of limited circumferentialand radial extent and constitutes a vaporizing zone. It is desirable butnot essential as the oil will normally extend over only a limited areaof the bottom wall before it is vaporized. This limited area is embracedwithin the term "vaporizing zone. An oil inlet opening 33 is formed inthe side 26a. of bottom wall 26 immediately over the sum 32. Oil inletopening 33 is suitably threaded to receive the threaded extremity of oilsupply pipe '24.

The side section 25 is provided with a series of what may be termedprimary air inlet openings 34 between its lower edge and the radiallyinwardly extending rib 29. These openings are of substantially but notexactly uniform size and are spaced substantially uniformly about amajor portion of the side section 25. As shown, there are six verticallyspaced horizontal rows. The lower row includes 26 openings ofapproximately .1 inch diameter. The second, third, fourth and fifthrows, counting from the bottom, would each designated by xs in thedrawings, no openings have been provided. These openings have beenomitted for a reason which will be explained presently. The top or sixthrow of primary air inlet openings includes 26 openings of approximately.09 inch diameter. The diameter of the lower edge, of th side wall isapproximately 10% inches. The diameter at the top of the burner isapproximately 11 inches, and the overall height of the side section 25is approximately 7% inches.

The side section 25 of the burner is composed of two halves, shown priorto bending, in Figures 4 and 5. The two blanks are perforated as shownby the small circles on each blank. The as indicate the spots where theopenings would be if they were equally spaced in each row, but have beenomitted as stated above. The two halves are bent into substantiallysemi-circular form and the ends joined by welding. The end C-D of theblank shown in Figure 4 is joined to the end C'D' of the blank shown inFigure 5. The ends AB and A'-B' are also joined together.

From the foregoing dimensions it will be seen that the openings 34 arenot of exactly uniform size and spacing, although approximately so.These openings are referred to as being of uniform size and spacing forwant of a better means of describing the size and spacing thereof. Theonly requisite in connection with the size and spacing of these openingsis that they be of such character as to permit localization of the zoneof combustion at various heights, within the burner, depending upon thevolume of oil admitted to the burner. This requirement will be describin further detail in comiection with the operation of the burner.

A series of additional air inlet openings 35 which may be referred to assecondary air inlet openings, are formed in the radially outwardlyextending rib 13a. There are 52 of these openings arranged in ahorizontal row, and they are of approximately .11 inch in diameter. Theopenings 35 are adapted to admit air into the burner between the topwall 21 and the anti-explosion ring 28, and to direct the same toward.the anti-explosion ring.

A generally disk-like partition or baflie 36 is positioned within t eburner 13 in an inclined position. The lower edge of the partition islocated above the lowermost row of openings 34 and above the oil inletopening 33. The upper edge of the partition 36 is located in thevicinity of the uppermost openings 34, preferably just under the next tothe highest row of openings. As here shown the partition is arranged sothat approximately one-third of the air inlet openings 34 are below thepartition and two-thirds of these'openings are above. This division ofthe openings 34 is considered desirable to obtain the bestcharacteristics at both low and intermediate fire, but may be variedwithin reasonable limits without destroying the advantage of the presentinvention.

As previously mentioned, the uniformity of spacing of openings 34 hasbeen destroyed by the omissionof openings at the points marked X. Thesepoints are those which, if provided with openings 34, the air enteringtherethrough would impinge directly against the baflle. It is importantthat this should not occur in order to avoid production of a luminousflame at points of impingement with resulting formation and deposit ofcarbon particles.

' The partition 36 is provided at its lower end with an integralprojection 36b, and the side section 25 has a recess 25a formed thereindirectly above the fuel inlet opening 33 into which the projection 36bis inserted. At'the upper end of the partition 36 is a foot 360 whichextends upwardly from the upper edge of the partition 36 to the underside of the top wall 21. In this manner the partition is firmly heldwithin the burner so that even if the burner is inverted the partition36 cannot be displaced. The partition is also provided with a singlerelatively large opening 36a at its center. The opening is preferablysomewhat smaller than the openings 21a in top wall 21. It is alsopreferably arranged in substantial but not necessarily exact alignmentwith opening 21a in top wall 21.

.In Figures 6 and '1 there is shown a burner 31 of the same generalconstruction and proportions as the burner 13 with the exceptionshereinafter noted. The bottom wall 38 of burner 31 has a cylindricalside portion 38a which is disposed inside of the perforated side section39. Side wall section 39 is provided with primary air inlet openings 40arranged substantially the same as openings 34 in burner l3. 3

A generally disk-like partition 4| is positioned within the burner 31 inan inclined position. The lower edge of the partition is located belowthe lowermost row of openings 40 and above the oil inlet opening 42. Theupper edge of the partition 4| is located in the vicinity ofthe'uppermost openings 40, preferably just under the next to the highestrow of openings. The partition is arranged so that approximatelyone-third of the air inlet openings 40 are below the partition and larouse two-thirds of these openings are above. This division of theopenings 40 is considered desirable for best "results.

The partition is provided with cooperating notches or recesses adjacentits lower edge adapted to engage the upper edge of the side portion 38aof the bottom 38 to locate the partition within the burner. Thepartition is also provided with a single relatively large opening 41awhich is spaced from the edge of the partition but is located nearer thelower edge than the upper edge. This opening is preferably somewhatsmaller than the opening 42a in top wall 42. It is also preferablyarranged in substantial but not necessarily exact alignment with opening42a in top wall 42.

The present invention resides in the combination with the burner of thebias partition. In order to appreciate the function ofthe partitionwithin the burner, it is necessary to describe the includesall burnerswhich operate on the principle of vaporizing oil in a pot, premixing airwith the oil vapors thus formed, and burning the premixture of oil andair vapor in a region remote from the surface of the liquid oil. Suchburners are exemplified by the present inventors prior Patents Nos.1,512,869 and 2,073,270.

In the burner of Figures 1 to 5, oil is delivered to the sump 32 fromthe oil inlet opening 33 and is initially ignited at that point by anysuitable form of ignition, either automatic, or by actually introducinga lighted taper. As soon as the oil has been ignited, the heat'from theresulting flame begins to vaporize the liquid oil. The vapors thusformed cannot, of course, be burned without admixing air therewith. Solong as but.

a limited quantity of oil vapors are generated, combusiton takes placebelow the partition 36, the necessary air being supplied from theopenings 34 which are located below the partition 36. However, when therate of vaporization of oil has reached a I point where the volume ofvapors generated exceeds that which forms a visibly combustible mixturewith the air available from the air inlet openings 34 below thepartition 36, visible combustion then occurs exclusively above thepartition 36. When that does occur, then all of the air introducedthrough the air inlet openings below the partitions 36 is being utilizedfor premixing with the oil vapors before combustion occurs.

,After combustion has been localized above the partition 36, a furtherincrease in the rate of vaporization of the oil (increasing the flow ofoil) will cause the zone of combustion to move up in the burner abovethe top wall 21. The number and size of the secondary air inlet openings35 and their arrangement with respect to the antiexplosion ring 26 aresuch that the lower limit of the zone of combustion will never passabove the anti-explosion ring 28. I

During the lower and intermediate stages of operation, i. e., whencombustion is located wholly or partially below the partition 36, thatpartition effectively excludes eddy currents from the lower portion ofthe burner, thus producing a stable operation of the burner at both thelower and intermediate operating stages. In the higher operating stages,i. e., when combustion is located above partition 36 and partially orWholly below top wall 21, the top wall effectively excludes eddycurrents from the upper portion of the burner. thus producing a stableoperation of the burner in its higher operating stages.

In this manner, opportunity is afforded for the natural premixing of airwith the oil vapors without interference from eddy currents or the like,before the vapors are burned during substantially all of the operatingstages of the burner. By operating stages, it is intended to exclude thelighting stage or the pilot stage when the burner operatesautomatically, at which stages the initial combustion occurs immediatelyover the surface of the oil. The ignition stage is of very shortduration.

It will, of course, be understood that combustion may be localized atvarious heights within the burner l3 by regulating the volume of oiladmitted to the burner. This is an inherent and distinctivecharacteristic of all vaporizing pot type burners. Thus, as previouslymentioned, when combustion is localized in the upper part of the burner,the air inlet openings 34 in the lower part of the burner serve tointroduce air for premixing in advance of combustion.

The operation of burner 31 is substantially the same as the operation ofburner I 3 just described. The only difference is that burner 31 willproduce a slightly lower clean fire than will burner I 3. However, thisadvantage of burner 31 is somewhat offset by the fact that there is atendency under certain adverse draft conditions for the lowest fire inburner 31 to be accidentally extinguished. The low fire in burner I3 isnot subject to such extinguishment. Except for the differences justmentioned, burners l3 and 31 operate in the same manner.

The term primary air inlet openings as used in the claims refers tothose openings which at.

certain stages of operation of the burner introduce air for pro-mixingand at other stages of operation introduce air directly to the zone ofcombustion. These openings are exemplified by the openings 34 of thisapplication.

The term secondary air inlet openings as used in the claims refers tothose openings which serve only to introduce air above or directly intothe zone of combustion and do not introduce air for pre-mixing with oilvapors in advance of combustion. These openings are exemplified by theopenings 35 of this application.

The scope of the invention is indicated in the appended claims.

I claim:

1. Combustion apparatus of the vaporizing pot type comprising a burnerprovided with a plurality of spaced apart primary air inlet openings, abottom wall for the burner, fuel supply means for delivering a quantityof liquid fuel to a section of the burner bottom wall constituting avaporizing zone, said vaporizing zone being located below and adjacentcertain of said primary air inlet openings, and bailie means positionedwithin the burner in an inclined position with the lower edge thereofdisposed adjacent the bottom of the burner in vertical alignment withthe vaporizing zone, the upper edge of the bailie means beingsubstantially removed from the bottom of the burner, said baille meansbeing constructed and arranged to provide for restricted communicationbetween the lower and upper portions of the burner.

2. Combustion apparatus of the vaporizing pot type comprising a burnerhaving a side wall provided with a plurality of spaced apart primary airinlet openings, fuel supply means for delivering a regulatable quantityof liquid fuel to the burner, said fuel supply means including a. fuelinlet opening formed in a wall of the burner below the lowermost primaryair inlet openings, and a partition disposed within the burner in aninclined position, the lower edge of the partition being positionedbetween the fuel inlet opening and the adjacent lowermost primary airinlet openings, said partition being constructed and arranged to providefor restricted communication between the lower and upper portions of theburner.

3. Combustion apparatus of the vaporizing pot type comprising a burnerhaving a side wall provided with a plurality of spaced apart primary airinlet openings, the burner including a bottom wall formed to provide avaporizing zone of limited area adjacent one side of the burner, fuelsupply means for delivering a regulatable quantity of fuel to thevaporizing zone, and an inclined partition disposed within the burnerwith a plurality of said primary air inlet openings therebelow and amajority of said primary air inlet openings thereabove, the lower edgeof the partition being disposedadjacent the bottom of the burner andimmediately above the vaporizing zone, the upper edge of the partitionbeing substantially removed from the bottom of the burner, the partitionbeing constructed and arranged to provide for restricted communicationbetween the lower and upper portions of the burner.

4. Combustion apparatus of the vaporizing pot type comprising a burnerhaving a top wall with an outlet opening therein and a side wallprovided with a plurality of vertically spaced horizontal rows ofprimary air inlet openings, means associated with said burner forcausing air to fiow through said primary air inlet openings into theburner and out of the'top thereof, fuel supply means for delivering aregulatable quantity of liquid fuel to the bottom of the burner, and acentrally apertured partition disposed within the burner with a portionthereof located below the lowermost primary air inlet openings, saidpartition being constructed and arranged with respect to the primary airinlet openings so that the air admitted through at least some of thelowermost primary air inlet openings passes beneath the body of saidpartition and upwardly through the central aperture therein.

5. A mechanism for burning liquid fuel which includes a chamber andmeans for admitting a liquid fuel to the bottom thereof, a wall for saidchamber provided with a plurality of primary'air apertures positioned ata plurality of heights above the level of the liquid fuel, said chamberbeing further provided adjacent its upper edge with secondary air inletmeans, and an apertured bafile positioned in said chamber and includinga portion located at a level below the lowest of said primary airapertures and a portion extend ing to a level above the lowest of saidprimary air apertures, whereby a portion of the lowest primary airapertures are located above said baflle and a portion below.

6. Combustion apparatus comprising a burner of the vaporizing pot typehaving a bottom wall and a side wall, the side wall being provided witha plurality of primary air inlet apertures at various levels, fuelsupply means for delivering. liquid fuel to the burner in regulatablequantities, and bafile means arranged within the burner in an inclinedposition with its upper edge located near the uppermost primary airinlet apertures and its lower edge located near the lowermost pri maryair inlet apertures, said bame means being formed toprovide forrestricted communication between the upper and lower parts of the burnerp t.

7. Combustion apparatus as defined in claim 6, wherein the primary airinlet apertures and the baflie means are so constructed and arranged asto substantially avoid any direct impingement of the primary air againstthe baflie means.

8. Combustion apparatus as defined in claim 6, wherein the means fordelivering liquid fuel to the burner includes a fuel inlet openingformed in a wall of the burner near the junction of the side wall andthe bottom wall, and wherein the battle means is arranged with its loweredge above and adjacent said fuel inlet opening.

9. Combustion apparatus as defined in claim 6, wherein the baflie meansconsists of a centrally apertured disk having its periphery arranged inclose proximity to the side wall of the burner pot.

10. Combustion apparatus as defined in claim 6, wherein the bailie meansin its entirety is arranged with at least some of the air inlet openingslocated above it and at least some of the air inlet openings locatedbelow it.

11. Combustion apparatus comprising a burner of the vaporizing pot typehaving a bottom I wall and a side wall, the side wall being providedwith a plurality of primary air inlet apertures arranged in verticallyspaced horizontal rows, fuel supply means for delivering liquid fuel tothe burner in regulatable quantities, and baflie means arranged withinthe burner with its median plane intersecting a plurality of the rows ofprimary air inlet apertures, said baflie means being formed to providefor restricted communication between the lower and upper parts of theburner pot.

12. Combustion apparatus as defined in claim 11, wherein the bafilemeans and the primary air inlet apertures are so constructed andarranged as to substantially avoid any direct impingement of the primaryair against the baffle means.

13. Combustion apparatus as defined in claim 11, wherein the baiilemeans consists of a centrally apertured disk having its peripheryarranged in close proximity to the side wall of the burner.

14. Combustion apparatus as defined in claim 11, wherein the means fordelivering liquid fuel to the burner includes a-fuel inlet openingformed in a wall of the burner near the junction of the side wall andthe bottom wall, and wherein the baffle means is arranged with its loweredge above and adjacent" said fuel inlet opening.

15. Combustion apparatus as defined in claim 11, wherein the bafflemeans in its entirety is arranged with at least one row of primary airinlet openings located above it and with at least one row of primary airinlet openings located below it.

BEN VALJEAN.

